There have been known processes for producing cyanohydrin compounds by reacting carbonyl compounds such as aldehyde compounds and ketones with hydrogen cyanide. Cyanohydrin compounds are useful as starting materials for synthesis of various compounds, e.g., for production of α-hydroxyester compounds, and various production processes have been developed for efficient production (Patent Literatures 1 to 7).
Conventionally, in particular, the development of a process for producing a cyanohydrin compound with use of a ketone has been advanced. As a process for producing a cyanohydrin compound with use of a ketone, Patent Literature 8 discloses a process for producing a deuterated cyanohydrin compound by reacting deuterated acetone with hydrogen cyanide.
In Patent Literature 8, deuterated acetone and hydrogen cyanide react with each other in a flow reactor to form a deuterated cyanohydrin compound that is high in rate of deuteration. The flow reactor is a reactor system into which the reactants are continuously introduced to react with each other and out of which the reaction product is discharged. By reacting deuterated acetone with hydrogen cyanide in such a flow reactor, a decrease in rate of deuteration of the deuterated cyanohydrin compound is prevented.
In producing a cyanohydrin compound with use of an aldehyde compound, a production process including the step of introducing hydrogen cyanide into a batch reactor containing an aldehyde compound in advance has conventionally been used. A reaction that involves the use of a batch reactor is sometimes referred to as “batch process”, by which the reactants are introduced into the reactor at a time and the reaction product is taken out after the reaction comes to equilibrium or after a certain rate of reaction is achieved. Such a process for producing a cyanohydrin compound with use of an aldehyde compound is disclosed in Patent Literature 1. In Patent Literature 1 a cyanohydrin compound is produced by introducing, into a reactor containing an aldehyde compound in advance, hydrogen cyanide gas diluted with inert gas.
Citation List
Patent Literature 1
Japanese Patent Application Publication, Tokukosho, No. 34-522 B (Publication Date: Feb. 9, 1959)
Patent Literature 2
Japanese Patent Application Publication, Tokukosho, No. 35-5755 B (Publication Date: May 25, 1960)
Patent Literature 3
Japanese Patent Application Publication, Tokukosho, No. 36-5869 B (Publication Date: May 26, 1961)
Patent Literature 4
Japanese Patent Application Publication, Tokukosho, No. 36-11965 B (Publication Date: Jul. 29, 1961)
Patent Literature 5
Japanese Patent Application Publication, Tokukosho, No. 36-12115 B (Publication Date: Jul. 31, 1961)
Patent Literature 6
Japanese Patent Application Publication, Tokukosho, No. 38-6761 B (Publication Date: May 22, 1963)
Patent Literature 7
Japanese Patent Application Publication, Tokukaihei, No. 10-25273 A (Publication Date: Jan. 27, 1998)
Patent Literature 8
Japanese Patent Application Publication, Tokukai, No. 2007-55953 A (Publication Date: Mar. 8, 2007)